How to Research Old Home Sites in New Hampshire: Historic Maps, LiDAR, Property Records & Field Clues

Researching a possible old home site or mill feature in New Hampshire can be rewarding, but it requires a careful, methodical approach. Historical research is about testing clues, not forcing them into a conclusion. A depression in terrain data or a building symbol on an old map may justify more research, but neither proves what the feature was, whether anything survives, who owns the land today, or whether detecting is allowed.

Step 1: Define the Question

Before you open a single map, know what you are looking for. Are you trying to find the original location of a specific family farm mentioned in a town history? Or are you scanning a broad area for signs of any early settlement? Defining your goal dictates which resources you consult first.

Step 2: Compare Historical and Current Topographic Maps

The USGS topoView tool is a strong starting point because it provides access to current US Topo maps and older editions in the Historical Topographic Map Collection. Compare multiple editions instead of relying on one sheet. Look for building symbols, roads that change or disappear, stream crossings, place names, schools, mills, and other mapped features. Map scale, survey date, and cartographic choices matter: small structures may be omitted and symbol placement may be approximate. Treat every mapped feature as a clue, not a guaranteed coordinate.

Step 3: Consult Sanborn Maps (Where Applicable)

If you are researching a developed village, town center, or industrial area, check the Library of Congress Sanborn Map collection. These large-scale fire-insurance maps can document building footprints, construction materials, street layouts, outbuildings, and industrial features. Coverage is strongest in mapped communities and commercial areas, so the absence of a Sanborn sheet does not mean a rural farm or small settlement did not exist.

Step 4: Analyze LiDAR Terrain Clues

LiDAR-derived bare-earth products can make subtle terrain easier to see beneath vegetation. Through UNH GRANIT’s LiDAR resources, examine hillshade and elevation products for possible cellar depressions, old road grades, stone-wall lines, terraces, mill races or channels, dams, and disturbed ground. Change the viewing angle or compare more than one visualization when possible. Natural pits, logging activity, modern drainage, quarrying, and data artifacts can resemble historic features. A geometric shape is a lead to investigate—not proof of a house, mill, road, or date.

Step 5: Build the Paper Trail

Maps and terrain make more sense when paired with records. Look for deeds and plans through the appropriate county registry, assessment and tax records through the town, and local context in town histories, historical-society collections, directories, census schedules, newspapers, and family papers. Historic aerial photographs can help show when fields became wooded, roads shifted, or buildings disappeared. Record the date, creator, repository, and page or image identifier for every useful source so another person can retrace your work.

Step 6: Check Current Parcels and Ownership

A cellar depression or abandoned-looking road is never “no man’s land.” Use the NH Geodata Portal and GRANIT parcel resources as starting points for parcel context, then verify current information with the appropriate municipal assessing office and official deed records. GIS boundaries can be generalized or out of date and are not a substitute for a survey. Do not publish an owner’s name, address, parcel identifier, or a screenshot that reveals a sensitive site.

Step 7: Get Permission Before Field Verification

Research does not create access rights. Before entering or detecting private property, secure explicit permission from the current owner and agree on boundaries, timing, finds, restoration, and privacy. For public or managed land, identify the responsible agency and verify its current rules. Read the NCRRMD New Hampshire laws guide before treating any mapped clue as a place to visit.

Step 8: Verify Carefully and Document the Result

With permission, compare the mapped or terrain clue with what is actually present. Note orientation, landform, stonework, road traces, water features, and modern disturbance without assuming that one clue settles the identification. Keep a research log separating observations from interpretations and unresolved questions. Share only broad labels such as “Northern New Hampshire” or “Coös County.” Never publish precise coordinates, directions to cellar holes, private addresses, owner details, or the locations of sensitive archaeological or historic resources.